Heart block is a problem in the electrical signals in the heart.
Normally, the heart beat starts in an area in the top chambers of the heart (atria). This area is the heart's pacemaker. The electrical signals travel to the lower chambers of the heart (ventricles). This keeps the heart beat steady and regular.
Heart block occurs when the electrical signal is slowed down or does not reach the bottom chambers of the heart. Your heart may beat slowly, or it may skip beats. Heart block may resolve on its own, or it may be permanent and require treatment.
There are three degrees of heart block. First-degree heart block is the mildest type and third-degree is the most severe.
First-degree heart block:
- Rarely has symptoms
Second-degree heart block:
- The electrical impulse may not reach the lower chambers of the heart.
- The heart may miss a beat or beats and may be slow and irregular.
- You may feel dizzy, faint, or have other symptoms.
Third-degree heart block:
- The electrical signal does not move to the lower chambers of the heart. In this case, the lower chambers beat at a much slower rhythm, and the upper and lower chambers do not beat at the same rate.
- The heart fails to pump enough blood to the body. This can lead to fainting and shortness of breath.
- This is an emergency that needs medical help right away.
AV Block; Arrhythmia; First-degree heart block; Second-degree heart block; Mobitz type 1; Wenckebach's block; Mobitz type II; Third-degree heart block
Heart block may be caused by:
- Medicine side effects. Heart block can be a side effect of digitalis, beta-blockers, calcium channel blockers, and other medicines.
- A heart attack that damages the electrical system in the heart.
- Heart diseases, such as heart valve disease and cardiac sarcoidosis.
- Some infections, such as Lyme disease.
- Heart surgery.
You may have heart block because you were born with it. You are more at risk for this if:
- You have a heart defect.
- Your mother has an autoimmune disease, such as lupus.